diff --git a/src/garage/tests/k2v/mod.rs b/src/garage/tests/k2v/mod.rs
index d9f3d36b..71093ccd 100644
--- a/src/garage/tests/k2v/mod.rs
+++ b/src/garage/tests/k2v/mod.rs
@@ -1,4 +1,5 @@
 pub mod item;
+pub mod poll;
 pub mod simple;
 
 use hyper::{Body, Response};
diff --git a/src/garage/tests/k2v/poll.rs b/src/garage/tests/k2v/poll.rs
new file mode 100644
index 00000000..70dc0410
--- /dev/null
+++ b/src/garage/tests/k2v/poll.rs
@@ -0,0 +1,98 @@
+use hyper::Method;
+use std::time::Duration;
+
+use crate::common;
+
+#[tokio::test]
+async fn test_poll() {
+	let ctx = common::context();
+	let bucket = ctx.create_bucket("test-k2v-poll");
+
+	// Write initial value
+	let res = ctx
+		.k2v
+		.request
+		.builder(bucket.clone())
+		.method(Method::PUT)
+		.path("root")
+		.query_param("sort_key", Some("test1"))
+		.body(b"Initial value".to_vec())
+		.send()
+		.await
+		.unwrap();
+	assert_eq!(res.status(), 200);
+
+	// Retrieve initial value to get its causality token
+	let res2 = ctx
+		.k2v
+		.request
+		.builder(bucket.clone())
+		.path("root")
+		.query_param("sort_key", Some("test1"))
+		.signed_header("accept", "application/octet-stream")
+		.send()
+		.await
+		.unwrap();
+	assert_eq!(res2.status(), 200);
+	let ct = res2
+		.headers()
+		.get("x-garage-causality-token")
+		.unwrap()
+		.to_str()
+		.unwrap()
+		.to_string();
+
+	let res2_body = hyper::body::to_bytes(res2.into_body())
+		.await
+		.unwrap()
+		.to_vec();
+	assert_eq!(res2_body, b"Initial value");
+
+	// Start poll operation
+	let poll = {
+		let bucket = bucket.clone();
+		let ct = ct.clone();
+		tokio::spawn(async move {
+			let ctx = common::context();
+			ctx.k2v
+				.request
+				.builder(bucket.clone())
+				.path("root")
+				.query_param("sort_key", Some("test1"))
+				.query_param("causality_token", Some(ct))
+				.query_param("timeout", Some("10"))
+				.signed_header("accept", "application/octet-stream")
+				.send()
+				.await
+		})
+	};
+
+	// Write new value that supersedes initial one
+	let res = ctx
+		.k2v
+		.request
+		.builder(bucket.clone())
+		.method(Method::PUT)
+		.path("root")
+		.query_param("sort_key", Some("test1"))
+		.signed_header("x-garage-causality-token", ct)
+		.body(b"New value".to_vec())
+		.send()
+		.await
+		.unwrap();
+	assert_eq!(res.status(), 200);
+
+	// Check poll finishes with correct value
+	let poll_res = tokio::select! {
+		_ = tokio::time::sleep(Duration::from_secs(10)) => panic!("poll did not terminate in time"),
+		res = poll => res.unwrap().unwrap(),
+	};
+
+	assert_eq!(poll_res.status(), 200);
+
+	let poll_res_body = hyper::body::to_bytes(poll_res.into_body())
+		.await
+		.unwrap()
+		.to_vec();
+	assert_eq!(poll_res_body, b"New value");
+}